Question

What is the equation in point-slope form of the line passing through (−2, 0) and (2, 8)?

Answer 1

well the point slope form is like this \[y-y_1 = m(x-x_{1})\]

Answer 2

A)y=2(x+2)
B)y=2(x-2)
C)y=-2(x-2)
D)y=-2(x+2)

Answer 3

i know, that's why im confused. Because the answers don't look like that. @Photon336

Answer 4

well first we can find the slope between the two points (-2,0) and (2,8)

\[\frac{ y_{2}-y_{1} }{ x_{2}-x_{1} } = m \]

Answer 5

m=2, right ?

Answer 6

\[\frac{0-8 }{-2-2 } = \frac{ -8 }{ -4 } = 2 \]

Answer 7

yay! i did that part right (:

Answer 8

now we know that m the slope is 2 now let's pick a point let's say (-2,0)

Answer 9

what do we do with it ?

Answer 10

We put it into this equation here: \[y-y_1 = m(x-x_{1})\]

Answer 11

m = 2, so now we have


We put it into this equation here: \[y-y_1 = 2(x-x_{1})\]

Answer 12

can you plug in (-2,0) in the appropriate places?

Answer 13

@unicornbeans

Answer 14

y-0=2(x+2) ?

Answer 15

OOOOOOHHHHHH !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 16

so that becomes

y = 2(x+2)

y = 2x+4

now let's test this. to see if it passes through our points. let's plug in (-2)

2(-2)+4 = 0 (-2,0)

y = 2x+4

y =2(2)+4 = 8 (2,8)

you can clearly see that this equation passes through both points.

Answer 17

So, is y=2(x+2) the answer then ?

Answer 18

what's your justification? why would it be the answer based on everything we said?